The invention relates generally to louvers and more particularly to louvers for selectively closing flow openings defined therethrough which may be used in conjunction with the radiator of a motor vehicle.
In DE-PS No. 34 38 709 a louver is disclosed which may be used with the radiator of a motor vehicle. The louver of this patent comprises a stationary support grid and a movable grid, each of which have equidistantly spaced grid rods which extend parallel to each other. The grid rods are relatively movable in a direction perpendicular to the longitudinal extent of the grid rod by an amount about equal to the spacing between the rods. The rods are movable from a first, at least partly overlapping position to control flow openings defined by the louver. In addition to the stationary grid, two relatively movable shift grids are provided which have relatively movable sliding surfaces exposed to the inflowing air. The problem with such louvers, besides a tendency to rattle, is that it is often difficult to adjust the louver because of stiffness or resistance to movement attributable to the tendency of the sliding surfaces to foul up. This fouling may be caused by particles carried with the inflowing air which are deposited on the sliding surfaces. If the louver does not open or close properly, the reliability and safety of the operation of the louver is not very satisfactory.
The invention is directed to the problem of providing a louver for selectively closing flow openings defined therethrough where the above-mentioned disadvantages do not occur. Thus, the louver of the invention, in addition to being of extremely sturdy construction, must have greatly reduced tendency to rattle and be largely insensitive to the impact of dirt particles carried by the inflowing air. Only in this manner can reliable and safe operation be ensured even in extreme situations.